Cotter has come in as an injury replacement for Leo Halavatau who picked up a calf injury against Wasps last weekend.
25-year-old Cotter, from Limerick, came through the Munster Academy and his last game for Munster was in the A Interprovincial against Ulster a week ago. He has been named as a replacement to face Bath in the Aviva Premiership tomorrow afternoon.
London Irish Director of Rugby Brian Smith said: “John Ryan did a fantastic job for us while he was here and we are sure Alan will make a similar impression.”
Show your "Exile-Style" and wear it with pride!